. >> reporter: frank, we're at napa's river front. we can see a surveillance camera over there, monitoring the public. now in the event of a crime that video and images from a cell phone are more and more likely to lead to a suspect. >> i would be looking for something to measure and calculate his height. i would be liking at the frame rate of the video. >> reporter: steve bowler showed us how enhancing grainy surveillance video can help investigators. >> clothing would be a factor too that i would be looking at. >> reporter: details that can help identify the shape of a person's face, clothing, or even what the person is holding in his hands. forensic experts, and police tell me video is often invaluable in situations such as the boston bombing. >> there's just so many videos out there. yeah, i think they'll find something. >> reporter: an advocate for the evidence in seeking truth. saying video forensics is a tool in finding the perpetrator and exonerating the accused. a team of people not only looking at surveillance video, but tho